SVN Changes not detected

Sometimes when i update my src vai svn (1.4 SVN-Server, IntelliJ 6.0.2
SVN Client) the changes are not detected in the editor.
I open a changed file but the changes are not in my code, after a few
minutes i get a message that file on disk is other than the memory
content and i have to manually add the changes to my file.
Only chance to be sure taht all svn-changes are in my code is to restart
IntelliJ after SVN-update.

mfg
Carsten